Special Containment Procedures: No personnel are to enter SCP-XXX's containment cell without approval from level 5 personnel. Any personnel which fail to comply will be administered amnesiacs and downgraded to level 0.

Description: SCP-XXX-1 is a primitive knife made from the rib of an unknown animal. Carbon dating has estimated the age of the knife to be [DATA EXPUNGED], making it the oldest man-made (presumably) tool known. However, it is in remarkably good condition for its age. Any human who has extended exposure to SCP-XXX-1 (including through indirect methods such as a video feed) feels a powerful desire to touch it. If they do, they will be infected and become an instance of SCP-XXX-2 (gloves cannot stop this effect; however, handling SCP-XXX-1 indirectly, such as with a robotic arm, will). SCP-XXX-2 will then progress through a series of stages:Stage 1 (immediately after contact): SCP-XXX-2 will become extremely possessive of SCP-XXX-2, expressing intense anger and/or sadness if they are seperated. SCP-XXX-2 will also display a high fever and profuse sweating. During this stage, if SCP-XXX-2 is seperated from SCP-XXX-1 for more than 24 hours, their symptoms will fade.Stage 2 (3-4 hours after contact): SCP-XXX-2 will become highly aggressive, lashing out at anyone who ventures too close or surprises them. They will also develop powerful pyschoses, hallucinating and speaking in an unknown language. During this stage, if SCP-XXX-2 is seperated from SCP-XXX-1, they will experience an epileptic seizure, often resulting in death. If they survive, their symptoms disappear.Stage 3 (5-8 hours after contact): SCP-XXX-2's skin will begin to develop black markings similar to tattoos. These markings resemble letters, presumably in the language that SCP-XXX-2 begins speaking once infected. SCP-XXX-2 apparently becomes unable unwilling (see Addendum #XXX-1) to speak other languages, including their native language, during this period. During this stage, if SCP-XXX-2 is seperated from SCP-XXX-1, they will experience an epileptic seizure followed by cardiac arrest. As of yet, no subjects have survived this.Stage 4 (10-15 hours after exposure): SCP-XXX-2 will begin to display strength, speed, and pain tolerance far beyond those an average human, as well as significantly hardened skin capable of resisting small arms fire. They will also become homicidal, attempting to kill any human they are aware of. Often, SCP-XXX-2 will cut out the hearts of their victims and [DATA EXPUNGED]. During this stage, SCP-XXX-2 can be seperated from SCP-XXX-1 with no effects aside from SCP-XXX-2 losing their enhanced abilities until they regain possession of SCP-XXX-1.

Addendum #1050-1: The following log is an account of a test to determine the exact nature of SCP-XXX's memetic abilities. Please note that although the first half of the test proceeded normally, the second half was an anomaly, which is why it is featured here.
D-5582 was told to enter the test chamber with a video camera and record the test. Dr. █████ oversaw the test and communicated with D-5582 through a speaker.

(all data beyond this point is classified and is not to be viewed by any personnel below level 4)

*SCP-XXX begins to move towards D-5582*D-5582: I'm not leaving my mother!Dr. █████: If you do not vacate the test chamber, I will be forced to call security!
*SCP-XXX is now standing behind D-5582*Dr. █████: I'm going to tell you one last time… Oh, shit.
*SCP-XXX appears to grab D-5582's shoulders, spin him around, and "stare" at his face*Dr. █████: I-I need a security team down here now!
*D-5582's body appears to flicker and becomes blurry, taking the appearance of SCP-XXXDr. █████: Oh Jesus… There's two of them…
*SCP-XXX and D-5582 move towards test chamber door as security team enters*[END LOG]

After the above log was created, SCP-XXX and D-5582 broke containment. Displaying unusually aggressive behavior, they proceeded to kill █ members of the security team and wound ██ more. Although SCP-XXX was recaptured, the whereabouts of D-5582 are unknown. Dr. █████ suggested upgrading SCP-XXX to Keter; the request is currently under consideration.